ROAD SAFETY AUDIT MAJOR HIGHWAY CROSS MEDIAN CRASHES ROUTE 3 HINGHAM AND WEYMOUTH

Transcription

1 ROAD SAFETY AUDIT MAJOR HIGHWAY CROSS MEDIAN CRASHES ROUTE 3 HINGHAM AND WEYMOUTH Prepared for Massachusetts Highway Department Prepared by MS Transportation Systems, Inc. Framingham, Massachusetts May 2009

2 ROAD SAFETY AUDIT MAJOR HIGHWAY CROSS MEDIAN CRASHES ROUTE 3 HINGHAM and WEYMOUTH FINAL REPORT May 2009 Prepared for Massachusetts Highway Department Prepared by MS Transportation Systems, Inc. 300 Howard Street P.O. Box 967 Framingham, Massachusetts Tel: Fax:

3 TABLE OF CONTENTS Page INTRODUCTION 1 RSA PROCESS 3 ANALYSIS 8 SUMMARY OF RSA FINDINGS/POTENTIAL ACTIONS 13 RECOMMENDATIONS 21 APPENDIX 24 Route 3 Hingham and Weymouth Road Safety Audit Page i

4 Introduction Lane departure crashes are one of the primary fatal crash types in Massachusetts. The Commonwealth exceeds the national average for the proportion of fatal lane departure crashes and was designated a lead state in lane departure crashes by the American Association of State Highway and Transportation Officials (AASHTO). The Massachusetts Highway Department (MassHighway) conducted a study of the problem and found that during , lane departure crashes accounted for 25 percent of all injury crashes and nearly half, 46 percent, of all fatal crashes. As part of the effort in implementing the safety plan and specifically reducing lane departure crashes, the MassHighway is completing a Road Safety Audit (RSA) Review Project specifically focused on median crossing (or median cross-over) crashes on its major highways. Road safety audits are a formal safety performance examination on existing or future roadways by an independent audit team. These specific audits are being conducted in locations where cross-over experience has been or has the potential to be of concern and where the RSA team has judged that factors exist that could affect the safety risk. During the audit, the RSA team works to identify opportunities for enhancing safety and to recommend specific enhancements intended to reduce median cross-over crashes and improve the overall safety along the highway. A RSA was conducted for Route 3 in Hingham and Weymouth as part of this project. Figure 1 indicates the corridor section under study, which was from approximately 5,500 feet north of Interchange 15 to 3,000 feet south of the interchange. This section had experienced a high number of median related crashes, including several cross-median crashes. Again, the purpose of this Route 3 Hingham-Weymouth RSA was to identify current conditions on the highway section under study that could potentially affect safety risk and to recommend a set of actions to address the identified safety factors. Recommendations contained in this report reflect the overall consent of the RSA team and do not necessarily reflect the official views of MassHighway. MS Transportation Systems, Inc. Page 1

5 Weymouth Hingham Interchange 15 Derby Street Route 3 Norwell Project Location W N E Route 3 Road Safety Audit Hingham - Weymouth, Massachusetts MS Transportation Systems, Inc. Framingham, Massachusetts S 1 : 25,000 FIGURE 1

6 RSA Process The general process outlined in the guideline 1 was essentially followed although with some minor variations incorporated in the overall procedure. These were due in part to the project location being a high speed, high volume section of an access controlled highway. With these characteristics, there are limited areas to safely stop and gather as a group along the section without potentially hindering traffic flow or the safety of the RSA team. Given the RSA team size and general character with the corridor, the team members who visited the site prior to the team meeting did so either individually or in smaller groups. A video recording of a drive-thru in both directions was collected by the RSA consultant and used at the meeting to review conditions as a group. Background material and plans were transmitted to the RSA consultant to compile and review prior to the initial RSA team meeting. Crash and traffic volume data were transmitted to RSA team members prior to the meeting as well. Once the initial RSA team meeting was conducted, the RSA consultant gathered the input completed the analysis and prepared a draft document for team members to review. Data including summary crash records for the period, two (2) detailed crash descriptions of crossover crashes, and available record highway plans were obtained and reviewed by the RSA consultant. RSA Team The following individuals participated in of the Route 3 Hingham and Weymouth Road Safety Audit: Bill Travers, MassHighway District 5 Brett Loosian, MassHighway District 4 Maintenance Maintenance Timothy White, FHWA Lisa Schletzbaum, MassHighway Safety Seth Asante, CTPS Management Unit Bonnie Polin, MassHighway Safety Lt. Daniel Mulkern, Mass State Police Management Unit Lyris Liautaud, MassHighway Highway Design William J. Scully, MS Transportation Systems (RSA Consultant) RSA Meeting A meeting was held on May 22, 2008 at the MassHighway District 5 Office. At the meeting, the RSA consultant provided a brief overview of the RSA purpose, a summary of the roadway section s characteristics and results of the review to date. The RSA team listed above was present at the meeting. The team included a range of safety expertise with different perspectives. The video record of the Route 3 taken while driving the corridor was viewed. During and following the video, discussions related to 1 MS Transportation Systems, Inc., Road Safety Audits, Median Cross-Over Crashes, Audit Guidelines, Prepared for MassHighway, October MS Transportation Systems, Inc. Page 3

7 the potential facts affecting the risk of safety related events along the corridor and possible solutions to reduce this risk were conducted. The RSA team provided input on the key items observed in the field and those items that were listed on the RSA Median Cross-Over Prompt List. Key items noted at the meeting included: A team member noted that there is a relatively short distance of open median-possibly 1,000 feet north and 1,000 south of interchange (distances were later checked and indicated approximately 3,500 feet of open median). Travel is allowed in shoulder during peak period in peak direction: NB 6AM 10AM, SB 3PM 7PM. The lane drop in the southbound direction contributes to the safety issues as a high volume must merge left and significant lane changing occurs as well. Compounding the issue is the travel in the shoulder during the PM peak hour in that direction. Within approximately ½ mile of the end of the lane drop is the exit ramp to Derby Street. Members of the RSA team felt that there is not sufficient warning to the lane drop. Better signage may be needed. With the use of the outside shoulder for travel, striping had been modified to provide a wider outside shoulder. This modification shifted all markings toward median which is the likely cause of the varying and narrow inside shoulder width. The Derby Street bridge was re-built a few years ago (between ) - one question was how the bridge project affected the crash data in the immediate area of the interchange. The section is dark and existing reflectors don t seem to be effective. It was mentioned that the recessed markers being put in I-93 (Randolph-Braintree Section) seem to work well. It was noted that a high proportion of the crashes occurred under dark conditions. With little room for error (i.e. narrow, inside shoulder) good visibility is critical and lighting may help. MS Transportation Systems, Inc. Page 4

8 It was noted that drainage problems exist and a number of crashes occurred when surface was wet and standing water had been cited. The combination of water, dark conditions and higher speeds during the dark periods, coupled with existing physical conditions likely contribute to median entry crashes. One area of the drainage problem was noted to be near Pleasant Street. Different surface between town lines (Weymouth/Hingham) was noted. Surface type may contribute to drainage problems. One section had more recent resurfacing. Most recent pavement rehab projects were completed: Weymouth townline to the North mid 90 s; and Hingham townline to the South in the early 2000 s. Relative to widening the inside shoulder to 4 feet it was asked if the reduction in unpaved median width could result in more crossings due to less width to slow down. Many of the team members (though not all) felt driving the section under study had a certain level of discomfort. Following the RSA meeting, the RSA consultant compiled the information, for inclusion on the analysis and in the development of recommendations. Analysis Procedures As previously indicated, the RSA analysis generally followed the procedure described in Guideline with some minor adjustments and also took into consideration the methods published by the Federal Highway Administration 2 and those included in training materials 3. The basic tasks included: Obtaining and reviewing crash and other traffic characteristic data and available record plans. Conducting site reconnaissance and collecting a current record of condition via photos and video, identify potential safety risk factors, and 2 Federal Highway Administration, FHWA Road Safety Audit Guidelines, Publication No. FHWA SA-06-06, Washington, D.C., Federal Highway Administration, Resource Center, Road Safety Audits Mini-Workshop, Jeffrey Shaw, PE, PTOE, presented to New England ITE Section, September 19, MS Transportation Systems, Inc. Page 5

9 Identify and evaluate potential actions to address the noted issues. In assessing the issues identified by the RSA Team, the relative seriousness and potential risk relative to crash frequency and severity were determined. Using the FHWA guidelines as input and considering characteristics of this specific RSA, the relative frequency criteria and severity criteria were identified and are presented in Table 1 and Table 2, respectively. Background information from FHWA is included in the Appendix. ESTIMATED TABLE 1 FREQUENCY RATING EXPECTED CRASH FREQUENCY (PER AUDIT ITEM) FREQUENCY RATING Exposure Probability high high 5 or more crashes per year Frequent medium high high medium 1 to 4 crashes per year Occasional medium medium low high high low Less than 1 crash per year, but Infrequent more than 1 crash every 5 years low medium medium low Less than 1 crash every 5 years Rare low low Source: FHWA RSA Training Workshop Typical Crashes Expected (per audit item) High-speed crashes; head on and rollover crashes Moderate-speed crashes; fixed object or off-road crashes Crashes involving medium to low speeds; lane changing or sideswipe crashes Crashes involving low to medium speeds; typical of rear-end or sideswipe crashes Source: FHWA RSA Training Workshop TABLE 2 SEVERITY RATING Expected Crash Severity Probable fatality or incapacitating injury Moderate to severe injury Minor to moderate injury Property damage only or minor injury Severity Rating Extreme High Moderate Low Taking into consideration both frequency and severity, the relative risk of a particular audit item was rated. The risk ratings are shown in Table 3. For each safety issue identified, the potential seriousness of the issue as well as possible mitigation measures have been indicated. MS Transportation Systems, Inc. Page 6

10 TABLE 3 CRASH RISK ASSESSMENT Frequency Rating Severity Rating Low Moderate High Extreme Frequent C D E F Occasional B C D E Infrequent A B C D Rare A A B C Source: FHWA RSA Training Workshop Crash Risk Ratings: A: minimal risk level D: significant risk level B: low risk level E: high risk level C: moderate risk level F: extreme risk level RSA Field Audit Audits were conducted by the team members prior to the RSA meeting. Key notes from the field work are as follows: In the southbound direction, entering the study section, motorists come into a horizontal curve on top of a grade at the end of guardrail - if in the inside lane, one can feel some discomfort due to being on the outside of the curve. Notices skid marks in area of vertical curve in beginning of study section in southbound direction. Entering the study section (SB) in three lanes from the north in the southbound direction, a lane drop occurs within 1,300 feet south of the Pleasant Street overpass that increases congestion and lane changing. There is travel in the shoulder during peak periods southbound in the PM peak period and northbound in the AM peak period. The inside shoulder was noted as varying width from nearly non-existent to two (2) feet rumble strip exists in some portions of inside shoulder but not all. There was some pavement edge raveling (inside) with areas of significant edge drop off. There was evidence of median entries in study section. MS Transportation Systems, Inc. Page 7

11 Analysis Route 3 in the study area is approximately 1.5 miles in length and is shown in Figure 2. In the north section (Weymouth), the roadway s horizontal alignment changes, the median is heavily vegetated and guardrail exists along the median edge. Through Interchange 15, Route 3 is a 4-lane divided, access-controlled highway. North of the interchange, an additional travel lane is gained in the northbound direction. In the southbound direction, a lane drop (3 to 2) occurs prior (approximately ¾ miles) to Interchange 15. Coupled with the allowed PM peak period travel in the southbound breakdown lane, the lane drop creates some difficult merging and lane changing. Some of the lane changing is done by motorists in the outside lane prior to the lane drop who must merge left and then shift back to the outside lane (shoulder/deceleration lane) to exit the highway at Interchange 15. Again, peak hour travel currently occurs in the shoulder. Route 3 Interchange 15 Derby Street Figure 2 - Study section As stated above, the existing cross-section of Route 3 in the interchange area and south of the interchange is a 4-lane section with two lanes per direction. Each of the travel lanes is 12 feet in width. The outside shoulder is feet in width as it functions as an auxiliary lane during the peak periods and must safely accommodate moving traffic. The inside shoulder varies in width in part due to the restriping that occurred when the peak period shoulder travel option was installed. A rumble strip exists along most of the study section (both inside and outside shoulders) although it is missing on the inside shoulder in spots. This condition may have been created when the Derby Street bridge overpass MS Transportation Systems, Inc. Page 8

12 was reconstructed and the Route 3 surface was modified to accommodate traffic through the construction zone. The rumble strips may simply not have been reinstalled once the bridge work had been completed. The overall alignment in the study area is varying but can be characterized as gentle. Through the interchange itself, Route 3 is level and tangent. Speed limits are posted at 60 miles per hour (mph). There are imbedded reflectors in the lane lines. The unpaved portion of the median width through the section ranges from approximately 42 to 48 feet. Measuring from edge line to edge line, the total median width is up to approximately 53 feet in width. The topography of the median varies over the length of the study section, but for the most part, it could be considered a depressed median with relatively flat slopes. The typical section plan showed slopes of 6 to 1, and based on field review, it appears they could be flatter in the majority of the section. While the length of the study section is approximately 1.5 miles, a review of the corridor shows that the length of the open median in this section is approximately 3,500 feet. This is divided with about 1,600 feet north of the interchange and the remaining 1,900 feet south of the interchange. Figures 3 through 6 present photographs depicting current conditions along the study section. Figure 3 Entering study section on Figure 4 Southbound at end of guardrail southbound direction section north of Interchange 15 Figure 5 Northbound On-Ramp Merge Figure 6 View of Cross-Section MS Transportation Systems, Inc. Page 9

13 A review of available safety data was completed as part of this RSA. The review of data included crash data reported for the years 2004 to The summary table and spot map are included in the appendix. Key aspects noted in the data included the following: A total of 60 median related crashes were noted during this period or an average of 15 median related crashes per year. Of the total median related crashes, only 2 or 3% were classified crossmedian crashes. One of the cross-median crashes reported was a fatal crash. This occurred in the immediate area of the interchange and the motorist was initially traveling southbound prior to crossing the median. Also, it appears that 24 crashes involved hitting the median guardrail and either remaining in the highway at the guardrail or bouncing off and crossing into and sometimes crossing each of the adjacent lanes to the right. Approximately 42% of the total median - related reported crashes resulted in personal injuries. Reported median - related crashes were split about evenly in NB and SB direction. Forty (40%) of crashes occurred during the non-light period (i.e. 9PM-5AM). Thirty-five percent (35%) of reported crashes occurred during rain or snow conditions. In general, the contributing causes varied but speed issues were noted in ten (10) of the crashes. Swerving to avoid something (i.e. object, animal) was noted in seven (7) crashes. Of the two cross-median crashes, erratic driving and alcohol were cited. In the cross-median fatal crash, it was noted the driver that initiated the crash was driving erratically including weaving before losing control in the area of the lane drop and open median. In addition, the fatal crash also resulted in several people injured and a total of six vehicles involved in the crash. The traffic volumes observed on Route 3 in this section were observed to be approximately 95,000 on an average weekday during October During the summer, volumes on Route 3 are approximately 9 percent above average month conditions based on nearby MassHighway permanent count data (Station No. 7318). MS Transportation Systems, Inc. Page 10

14 Based on the count station, October volumes approximate average month conditions. Figure 7 depicts the hourly volume by direction in October 2006 south of Derby Street (Interchange 15). As shown, PM peak period flows in the peak direction exceed 4,000 vehicles per hour. Figure 7 Route 3 Directional Volume Figure 8 illustrates the variation in flow on Route 3 over the year based on data from the MassHighway permanent count Station No Average Daily Volume 120, ,000 80,000 60,000 40,000 20,000 0 AADT 95,000 +/- JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure 8 Route 3 Monthly Traffic Volume MS Transportation Systems, Inc. Page 11

15 A review of available truck count data indicates that on Route 3, truck volumes tend to represent approximately 5 percent of the daily total volume as well as during the peak hour. This translates to approximately 5,000 trucks over the course of the day and 380 trucks during the peak hour. In summary, the Route 3 RSA in Hingham has identified a number of physical and operational characteristics as being potentially a contributing factors to increasing the risk of experiencing the safety issues although each with varied levels of seriousness. The major ones include: Median is largely open (i.e. no barriers), has a slope of 6:1 or flatter and was considered by the RSA team as highly crossable, The median as measured from inside edge line to inside edge line is relatively narrow 53 feet or less. High volumes (approximately 95,000) on average weekday. Combination of the interchange movements, peak period travel in shoulder, southbound lane drop and high volume results in substantial amount of lane changing in short distance. The next section will discuss these key issues and the potential actions to consider for addressing them. MS Transportation Systems, Inc. Page 12

16 Summary of RSA Findings/Potential Actions Based on the field review, the review of crash data and discussions among the RSA team members, the issues related to the safe operating conditions of the Route 3 in the Hingham area were identified. There were a number of factors or issues of concern that were identified as potentially having an effect on the risk and these are listed in Table 4 along with the assigned risk rating. TABLE 4 SUMMARY OF FACTORS THAT POTENTIALLY AFFECT THE RISK OF SAFETY RELATED EVENTS Factor or Issue Median width is 53 feet or less and open for approximately 3,500 feet in two sections north and south of the interchange Varying width of inside shoulder - rumble strip is absent in certain areas Condition of non-paved area just off inside paved shoulder - Edge drop off appears significant in certain areas SB horizontal curve at beginning of study section may affect driver control and visibility - north of interchange there is an elevation difference between the two directions High travel speeds excessive lane changing improper driver behavior The acceleration-deceleration lanes appear to be shorter than ideal Pavement broken up around some catch basins located in inside shoulder ponding of water reported in several areas but most notably near Pleasant Street Peak period travel in the shoulder Southbound lane drop occurs approximately 3,400 feet prior to Interchange Section is dark affecting ability to follow roadway Risk Rating D 1 D D C D C C C D C 1) risk rating based on reported cross-median crashes. Total reported median entry crashes average 15 per year. Given the high volume and the high number of median entries, the open median factor was assigned a high risk factor. In other words, the operational and physical characteristics of the highway section under study is such that once a motorist makes a mistake or becomes errant and enters the median, there is a relatively high probability that the motorist will cross the median and enter the opposing direction of flow. Recent historical information shows a relatively small number (3) of median related crashes (reported) actually involve crossing the median. With observed volumes approximately 95,000 vehicles per day, the exposure is considered high and this type of event MS Transportation Systems, Inc. Page 13

17 becomes a greater possibility. Although exposure is high, the median width relatively narrow, and the RSA team could sense a certain uneasiness in traveling this study section, a risk rating of D was assigned. It was recognized, however, that a high number of median entries occur and the potential of crossing the open median areas could be considered highly possible based on its topography. One of the more substantive items noted by the RSA team was the existing lane drop in the southbound direction. It occurs approximately 3,400 feet north of the Interchange 15 exit ramp. The southbound direction is the peak direction during the PM peak hour which experiences volumes in excess of 4,000 vehicles per hour for several hours (based on October data). Under present conditions, travel is also allowed in the shoulder between 3:00 PM and 7:00 PM. Consequently, during the PM peak period, increased volume in the shoulder, the lane drop, high volumes and the exit at the Hingham interchange combine result to in a high level of lane changing and the possibility of a median related event. Risk ratings assigned to the lane drop and high travel speeds were D. The peak hour travel in the shoulder appears to be a factor in median related crashes in general. Travel in the shoulder affects driver behavior particularly at the on- and offramps in relation to merging and lane changing. Providing for travel in the shoulders has meant re-striping the lanes on this section resulting in a narrow and varying width inside shoulder. A C rating relative to cross-median risk was assigned to travel in the outside shoulder. With the narrow inside shoulder, rumble strips are not fully provided and if they do exist, there is virtually no room for error. In other words, if a motorist hits the rumble strip on the inside shoulder, there is a good chance that the motorist will not react in sufficient time to keep the vehicle on the road. A risk rating of D was assigned to this factor. There were also noticeable areas where the edge drop off was significant which was also rated a D. The roadway geometry was also cited as a potential factor in southbound travel. There is horizontal curve with some vertical grade change as one enters the study section from the north. It was noted that visibility on roadway conditions ahead may be somewhat affected. This occurs at or near the area of the lane drop. A factor of C was assigned. There were several crashes that reported standing water and wet surface. Members of the RSA team confirmed this and it could be in part due to the pavement surface and partially due to inadequate drainage in certain location. One area cited is near the Pleasant Street overpass. This factor was assigned a C rating. High travel speeds and excessive lane changing ( D risk rating) were noted by members of the RSA team. MS Transportation Systems, Inc. Page 14

18 Also, the acceleration-deceleration lanes were noted as being shorter than desirable and were assigned a C rating. Lastly, several RSA team members noted the study section was notably dark during evening and nighttime conditions affecting motorists ability to follow the road. This factor was assigned a C. Suggested actions identified are intended to reduce or eliminate cross-median crashes and enhance overall safety were identified based on the specific issue. Given the primary objective of this RSA program is to address cross-median crashes, the first action evaluated was the potential of a median barrier. The following paragraphs include discussion pertaining to the evaluation of a median barrier. Consideration of a Median Barrier One of the more significant actions to be considered is to install median barriers in the current open areas. A barrier can be considered when there is a higher than desirable chance or a greater risk for cross-median crashes to occur and that have or could result in fatalities and/or a high proportion of injury related crashes. In addition, a barrier could be considered when the consequences or severity of a crash are worse than if the barrier were in place. Factors taken into account in deciding on whether a median should be installed involve the following: High volumes and speeds Truck volumes and mix Narrow median History of cross-median crashes High risk of catastrophic event These items have been reviewed relative to the Route 3 section under study. Figure 9 presents a review of the corridor in relation to the median warrant criteria presented in the AASHTO RDG 4. As can be seen in the diagram, with the median (as measured from edge line to edge line) is approximately feet and a volume of 95,000 vehicles on an average day, the intersection of the two items is in the area of the chart where a barrier should be considered. With the volume, the result in an intersecting point in the chart area where a barrier should be considered. 4 American Association of State Highway and Transportation Officials, Roadside Design Guide, Washington, D.C., 2002, Chapter 6 Update MS Transportation Systems, Inc. Page 15

19 95,000 ADT 80 median width feet ADT - 95, AVERAGE DAILY TRAFFIC (thousands) BARRIER RECOMMENDED BARRIER CONSIDERED BARRIER OPTIONAL Analysis of Median Barrier Warrant Route 3 Road Safety Audit Hingham and Weymouth, Massachusetts MEDIAN WIDTH (feet) Source: AASHTO Roadside Design Guide, Chapter 6 Update, 2006 MS Transportation Systems, Inc. Framingham, Massachusetts Figure 9

20 In addition to the chart and related warrant criteria, which is a guideline, further consideration was given to the following: The high volume presents a likelihood of greater number of errant vehicles entering the median, A fairly high number of median entries over the four (4) year period and the median appear to be very crossable. Consequently, based on the analysis of the data, the field drive-thru and discussion of the conditions by the RSA team members, it is suggested that a median barrier be installed in the section of the study section that are currently open and crossable. This installation will be approximately 3,500 feet of barrier to be installed. The selection of the barrier is discussed in the next section. Barrier Selection There are a number of barrier types that can be considered in addressing the median cross-over crashes. These include the following: Weak post W-Beam Box Beam Generic Low Tension Cable High Tension Cable Barrier Strong post W-Beam Thrie Beam Concrete (Jersey) From a cost and aesthetic perspective, the cable (flexible) barrier has its advantages over the various guardrail systems or concrete barrier. The median slope and/or recovery area also affects the use and placement of any barrier including guardrail. With regard to the cable barrier, the RSA team has discussed two primary cable alternatives noted below. In addition to the cable barrier systems, team members also suggested that guardrail be considered in the evaluation. The alternative types of guardrail were reviewed for potential application on this route. Considerations included the volume of traffic, relative amount of truck traffic and travel speeds. Based on these, the most applicable types of guardrail for this study section include the strong post thrie-beam or cable barrier. The guardrail is appropriate for high speed highways that have high volumes with a relatively high proportion of truck traffic. The weak post W-beam and box beam can be eliminated due to the type of highway. The concrete barrier would generally be applicable in urban sections with limited median widths available, which is not the situation in this section. MS Transportation Systems, Inc. Page 17

21 In deciding on the type of barrier, recommended guidelines in selection are included in Table 5 taken from the AASHTO Roadside Design Guide 5. Criteria TABLE 5 CRITERIA FOR BARRIER SELECTION Comments 1. Performance Capability Barrier must be structurally able to contain and redirect design vehicle. 2. Deflection Expected deflection of barrier should not exceed available deflection distance. 3. Site Conditions Slope approaching the barrier and distance from traveled way may preclude use of some barrier types. 4. Compatibility Barrier must be compatible with planned end anchor and capable of transitioning to other barrier systems (such as bridge railings). 5. Cost Standard barrier systems are relatively consistent in cost, but high-performance railings can cost significantly more. 6. Maintenance A. Routine Few systems require a significant amount of routine maintenance. B. Collision Generally, flexible or semi-rigid systems require significantly more maintenance after a collision than rigid or high-performance railings. C. Material Storage The fewer different systems used, the fewer inventory items/storage space required. D. Simplicity Simpler designs, besides costing less, are more likely to be reconstructed properly by field personnel. 7. Aesthetics Occasionally, barrier aesthetics are an important consideration in selection. 8. Field Experience The performance and maintenance requirements of existing systems should be monitored to identify problems that could be lessened or eliminated by using a difference barrier type. Source: AASHTO, Roadside Design Guide, 2002, Chapter 5 Roadside Barriers. Maintenance issues are also an important consideration in decisions regarding median barrier installations. The maintenance issues that are of concern include: Barrier hits per mile Frequency of hits Cost recovery Cable downtime Repair effect on traffic Maintaining tension 5 American Association of State Highway and Transportation Officials, Roadside Design Guide, Washington, D.C., 2002, Chapter 6 Update MS Transportation Systems, Inc. Page 18

22 Final selection of the barrier type should be based on the costs, the ability to maintain a recovery zone, and likely maintenance or repair requirements. In addition, aesthetics and the characteristics of the recent crashes can also be taken into account. The key points of the cable barrier or guardrail are summarized below. Cable Barrier While the low tension generic cable system has been in existence for more than 50 years, most of the recent cable system research and installation is focused on the high tension systems. There are currently six (6) manufacturers with systems approved by the Federal Highway Administration (FHWA) for use under certain conditions. There are 3-rope or 4-rope cable systems as shown in the following two photographs. This barrier can be installed on slopes of 6:1 or flatter with little constraint on placement other than deflection limits. There are certain systems (Brifen and Gibraltor 4 rope) that have been approved for slopes as steep as 4:1. The cable can usually be installed sufficiently away from the paved surface so as to maintain a clear zone or recovery area and to minimize hits. More constraints on placement exist when installing the barrier on slopes steeper than 6:1. The topography and median width in the Hingham Weymouth study section should accommodate cable barrier. 4 Rope Brifen System 3 Cable CASS System Guardrail Typically, guardrail is used where steep slopes or minimal recovery zones exist within close proximity to the pavement surface. Guardrail is also utilized where the median width is narrow and low deflections are required. In addition, guardrail can be placed in the median where slopes are 10:1 or flatter. With the guardrail placed within several feet of the pavement edge, the clear zone (or recovery area) would be eliminated at least on one side. Deflection with the thrie-beam rail is in the 2 to 3 foot range. One consequence MS Transportation Systems, Inc. Page 19

23 of the guardrail placed at the edge of pavement is that there is a bounce off effect when struck by a vehicle. This can potentially increase the number of vehicles affected in the crash. Thrie-beam guardrail is used in the northern area of the study section where median obstruction exist or the roadside slopes are relatively steep. Per mile costs of the two basic types of median barrier treatment to be considered are summarized in Table 6. The costs are based on MassHighway unit prices with planning level assumptions and contingencies. In general, installation costs for the cable barrier tend to be lower than guardrail costs. TABLE 6 COMPARISON PER MILE COSTS Cable vs. Guardrail Costs/Mile Cable $144,000 Thrie beam $213, assumes single run & double faced thrie-beam The section under study in Hingham and Weymouth has a median width and topography that could accommodate a cable barrier. The placement could be sufficiently off the pavement edge to allow for recovery. Assuming cable barrier is used in the estimated 3,500 feet of open median, a $125,000 cost is projected. If guardrail were to be used, it likely needs to be placed within a few feet of the pavement edge. If this is the case, single faced guardrail could be placed in both directions of Route 3 or double faced in a single direction. Although preventing cross-over crashes, one disadvantage of the guardrail would be vehicles deflecting off of it back into the traffic lanes possibly creating multiple vehicle crashes. Costs for a single run of double faced thrie-beam in the open median sections is estimated to cost $140,600. The next section outlines a set of recommendations that address all the factors including but not limited to the open median. MS Transportation Systems, Inc. Page 20

24 Recommendations As a result of the RSA analysis and team input, a set of recommendations have been identified and are summarized in Table 7. Identified in the table in addition to the risk factor and recommended action are the estimated costs and potential timeframe (i.e. short (0-1 year), medium (1-3 years) and long (>3 years)). These actions are intended to eliminate the chance of cross-median crashes as well as reduce the severity of all crashes and improve the overall safety condition of this section of Route 3 in Hingham and Weymouth. A major recommendation by the RSA team is to install a median barrier in the existing open median both north and south of the interchange. While some members of the team suggested extending the existing guardrail, the extension would apply only in the approximately 1,600 foot section north of the interchange. South of the interchange is currently open without guardrail sections. Consequently, a new barrier would need to be installed for about 1,900 feet. One option involves placing guardrail on one side of within a few feet of the pavement edge. As stated previously, one consequence is that the guardrail can result in redirecting the motorist back into the travel lanes, which if the motorists cannot recover adequately, will result in potentially more serious crashes and greater impact on traffic operations. Installing guardrail could also require work in relation to the inside shoulder and median sections adjacent to the pavement. Although this additional work would be positive and are included in other recommendations listed by the RSA team, it may result in a higher implementation cost in the short range. An alternative is to install a cable barrier. The cable barrier could likely be installed independent of both widening the inside shoulder and regrading some of the median near the pavement edge in the short range. The cable barrier would be a lower cost action, prevent cross-median events and allow for a recovery area in both directions. For these reasons, the RSA team recommends that cable barrier be given first consideration as to the type of barrier in this study section. In addition to the barrier, addressing the lane drop is another major action that the RSA team believes important in addressing lane changing and median safety in this section. To this end, it is recommended that the existing third lane be carried through the interchange where the lane drop can be more safely transitioned. While this action is more of a long term action, improving the lane drop warnings to motorists through enhanced signage should be accomplished in the short term. While improved signage would ideally include overhead signage (possibly electronic VMS), this would be a higher cost action and could result in a longer implementation time. An alternative to the overhead sign would be the use of oversized signs (5 x5 ) with supplemental distances MS Transportation Systems, Inc. Page 21

25 added to the signs. A concept of this is included in the Appendix. This lower cost option could be implemented in the short term and serve as an interim improvement at a minimum. Risk Factor Median width is 53 feet or less and open for approximately 3,500 feet through the interchange Varying width of inside shoulder - rumble strip is absent in certain areas Condition of non-paved area just off inside paved shoulder - Edge drop off appears significant in certain areas SB horizontal curve may affect driver control and visibility - north of interchange there is an elevation difference between the two directions High travel speeds excessive lane changing improper driver behavior Acceleration-deceleraton lanes appear to be shorter than ideal TABLE 7 SUMMARY OF RECOMMENDATIONS Risk Recommended Estimated Estimated Rating Action Cost Timeframe D Install cable barrier $125,000 short term D D C Widen inside shoulder Re-install rumble strips Re-establish unpaved portion of median addressing edge Install safety edge Install flexible, reflective delineators $1.9M $6,000 TBD (low) could be done as part of inside shoulder work 1-2% of total resurface cost long term long term short term long term $2,000 short term D Increase enforcement TBD short term C Improve markings Widen outside shoulder TBD (low) TBD (high) short term long term Pavement broken up around catch basins located in shoulder ponding of water reported in several areas but most notably near Pleasant Street C Repair pavement Drainage improvements - Pleasant Street area TBD long term as part of rehabilita tion Peak period travel in shoulder C Improve signage of travel use added warnings Southbound lane drop occurs approximately 3,400 feet prior to Interchange Section is dark affecting ability to follow roadway D C Install new roadside signage and markings of the lane drop (3-4 signs) Use of VMS overhead signs Extend lane through interchange Improve delineation with flexible reflector posts Install lighting at interchange $5,000 short term $10,000 TBD $900,000 see above TBD (high) short term long term long term short term long term MS Transportation Systems, Inc. Page 22

26 Other actions suggested include improving signage for travel in the breakdown lane, addressing drainage issues and improving the inside shoulder including a new, complete rumble strip. The inside shoulder widening is a higher cost item. Assuming a conservative widening of 6 feet (including a 3-foot box widening section in the existing travel lane) on both sides, the cost is estimated at $1.9M with approximately 16,000 feet of work. While in the short term signage and markings can be implemented to improve the southbound lane drop guidance, a long term solution suggested by the team was to extend the third lane through the interchange. It is assumed this would entail widening the southbound section by approximately 12 feet for a length of approximately 5,500 feet. The estimated cost for that action is $900,000 assuming minimal work is necessary in the area of the Derby Street overpass. Short term, low cost actions to address the darkness factor would be to install flexible delineator posts along the median edge in both directions. In the long term, consideration for lighting at the interchange can be given, however, this is a higher cost action that has also been noted by the RSA team members will result in higher cost maintenance requirements. MS Transportation Systems, Inc. Page 23

27 Appendix RSA Meeting Agenda RSA Attendees List Median Crash Diagram Crash Data Traffic Volume Data MS Transportation Systems, Inc. Page 24

28 Road Safety Audit Hingham Route 3 Meeting Location: MassHighway District 5 Office 1000 County Street, Taunton Thursday, May 22, :00 AM 12:00 PM Type of meeting: Attendees: Please bring: Cross Median Road Safety Audit Invited Participants to Comprise a Multidisciplinary Team Thoughts and Enthusiasm!! 10:00 AM Welcome and Introductions 10:15 AM Introduction to Road Safety Audits and Cross Median Crashes 10:30 AM Review of Site Specific Material Crash & Volume Summaries provided in advance Existing Geometries and Conditions Video and Images 11:00 AM Completion of RSA Identification of Safety Concerns using RSA Prompt List as a guide Identification of Possible Countermeasures 12:00 PM Adjourn for the Day but the RSA has not ended Instructions for Participants: Before attending the RSA on May 22nd participants are encouraged to drive Route 3 in Hingham (Interchanges 14-16) and complete/consider elements on the RSA Prompt List with a focus on safety factors affecting cross median crashes. All participants will be actively involved in the process throughout. Participants are encouraged to come with thoughts and ideas, but are reminded that the synergy that develops and respect for others opinions are key elements to the success of the overall RSA process. After the initial RSA meeting, participants will be asked to comment and respond to the document materials to assure it is reflective of the RSA completed by the multidisciplinary team.

29 ROAD SAFETY AUDIT MEETING Route 3 Hingham - May 22, 2008 Attendance List Name Agency/Dept. Tim White FHWA Timothy.A.White@fhwa.dot.gov Bill Travers MHD Dist. 3 Highway Maint. Bill.Travers@mhd.state.ma.us Seth Asante CTPS Setha@ctps.org Lyris Liautaud MHD Lyris.Liautaud@mhd.state.ma.us Brett Loosian MHD Dist. 4 Highway Maint. Brett.Loosian@mhd.state.ma.us Robert Gregory MHD Dist. 5 Robert.Gregory@mhd.state.ma.us Lisa Schletzbaum MHD - Safety Lisa.Schletzbaum@mhd.state.ma.us Bonnie Polin MHD - Safety bonnie.polin@mhd.state.ma.us Dan Mulkern MSP Bill Scully MS Transportation Systmes, Inc. msinatick@earthlink.net

30 WINTER COURT MIDDLE STREET Route 3 Median Crashes WASHINGTON STREET PLEASANT STREET WARD STREET ± 1 2 MILL STREET WEST STREET FRONT STREET ") 18 ") Crash IDs between CUSHING STREET PARK AVENUE WEST COLUMBIAN STREET WEYMOUTH PARK AVENUE RALPH TALBOT STREET OAK STREET 37 ") HINGHAM DERBY STREET GARDNER STREET WHITING STREET Legend Type of Median Crash * Major Roads Crash IDs between Cross Median, Fatal Crash Cross Median, Non-Fatal Crash RANDOLPH STREET Median, Non-Fatal Crash HOLLIS STREET Municipal Boundary UNION STREET Interstate Principal Arterial CENTRAL STREET Minor Arterial Collector Local ") POND STREET LIBERTY STREET SHARP STREET ROCKLAND

31 MASSACHUSETTS HIGHWAY SAFETY DIVISION CRASH SUMMARY REVISED NO. ROADWAY: STUDY PERIOD: CRASH NUMBER RT 3 CITY: ROCKLAND, HINGHAM, WEYMOUTH 1/1/2004 TO 12/31/2007 LOCATION: NEAR EXIT#15 TRAVEL LIGHT WEATHER ROAD REASON FOR VEHICLE MEDIAN OR CROSS DRIVER CONTRIBUTING CRASH LANES CONDITION CONDITION SURFACE RUNNING OFF ROAD LEFT MOVEMENT MEDIAN CRASHES CAUSE SEVERITY SB Dark - Lighted Rain Wet Lost control of vehicle in heavy thunderstorms and hydroplaned Travel Lane to Median Barrier Median No Improper Driving Non-Fatal Injury SB Dark - Not Lighted Rain Wet Lost control of vehicle Travel Lane to Median Concrete Barrier Median Failure to keep in proper lane Property Damage Only SB Daylight Clear Dry Vehicle was cut-off by unknown vehicle and hit another vehicle in the rear Travel Lane to Median Jersey Barrier Median Swerving or avoiding due to vehicle in roadway Non-Fatal Injury SB Daylight Clear Dry Vehicle tried to avoid tire debris on the roadway and hit median barrier Travel Lane to Median Barrier Median Swerving or avoiding due to object in roadway Property Damage Only SB Daylight Rain Wet Lost control of vehicle on wet surface and hit another vehicle on the right side Travel Lane to Median Guardrail Median No Improper Driving Non-Fatal Injury SB Daylight Clear Dry Lost control of vehicle and hit median guardrail Travel Lane to Median Guardrail Median Operating Vehicle in Erratic, Reckless Manner Property Damage Only SB Dark - Not Lighted Rain Wet Lost control of vehicle and overturned Travel Lane to Middle of the Median Median Failure to keep in proper lane Non-Fatal Injury SB Dark - Not Lighted Rain Wet Lost control of vehicle Travel Lane to Median Guardrail to Trees in the Median Median Failure to keep in proper lane Non-Fatal Injury SB Dark - Lighted Rain Wet Lost control of vehicle and overturned Travel Lane to Median Guardrail to the Right Guardrail Median No Improper Driving Non-Fatal Injury NB Dark - Not Lighted Rain Wet Vehicle hit standing water and hydroplaned Travel Lane to Median Guardrail to Trees in the Median Median Exceeded Speed Limit Property Damage Only NB Dark - Not Lighted Rain Wet Vehicle hit standing water and hydroplaned Travel Lane to Right Guardrail to Median Guardrail Median Driving too fast for condition Property Damage Only NB Dawn Clear Dry Vehicle changed lanes to an already occupied lane and struck the side of another vehicle Travel Lane to Trees in the Median Median Failure to keep in proper lane Property Damage Only NB Daylight Clear Dry Lost control of vehicle for unknown reason and was struck by another vehicle on the side Travel Lane to Median Barrier Median Failure to keep in proper lane Non-Fatal Injury NB Dawn Rain Wet Vehicle hit standing water and spun into median guardrail Travel Lane to Median Guardrail Median No Improper Driving Property Damage Only NB Daylight Clear Dry After mechanical failure vehicle rear ended another vehicle and swerved into the median Travel Lane to Median to Breakdown Lane to Old Rest Area Exit Sign Median No Improper Driving Property Damage Only NB Daylight Rain Wet Lost control of vehicle due to bad tires Travel Lane to Median Guardrail Median Operating defective equipment Property Damage Only NB Dark - Not Lighted Rain Wet Lost control of vehicle and hydroplaned due to tractor trailer speeding behind vehicle Travel Lane to Median End of Guardrail Median Exceeded Speed Limit Property Damage Only SB Dusk Snow Snow Lost control of vehicle for unknown reason Travel Lane to Median Barrier to the Trees in the Right Shoulder Median Failure to keep in proper lane Property Damage Only SB Dark - Not Lighted Cloudy Not Reported Lost control of vehicle and ran off road to the left Travel Lane to Trees in the Median Median Failure to keep in proper lane Property Damage Only SB Dawn Rain Wet Vehicle hit standing water and overturned Travel Lane to Median Ditch Median No Improper Driving Property Damage Only SB Dark - Not Lighted Clear Dry Lost control of vehicle for unknown reasons Travel Lane to Median Guardrail to the Right Breakdown Lane Median Failure to keep in proper lane Property Damage Only SB Dark - Not Lighted Clear Dry Distracted due seeing something in the rear view mirror, swerved to the left and right and overturned Travel Lane to Median Brush Median Over-correcting/Over-steering Non-Fatal Injury SB Dark - Lighted Rain Wet Vehicle was cut-off by unknown vehicle Travel Lane to Median Guardrail to the Right Breakdown Lane Median Swerving or avoiding due to vehicle in roadway Non-Fatal Injury SB Daylight Rain Wet Lost control of vehicle Travel Lane to Trees in the Median Median No Improper Driving Not Reported NB Daylight Clear Dry Lost control of vehicle and overturned Travel Lane to Median Embankment Median Failure to keep in proper lane Non-Fatal Injury NB Daylight Rain Wet Lost control of vehicle on wet surface and hit another vehicle on the right side Travel Lane to Median Guardrail to the Right Breakdown Lane Median Swerving due to slippery surface in roadway Property Damage Only NB Dark - Not Lighted Rain Water Vehicle hit standing water and spun into median guardrail Travel Lane to Median Guardrail to the Right Guardrail Median Driving too fast for condition Property Damage Only SB Dark - Not Lighted Rain Wet Vehicle hit standing water and hydroplaned Travel Lane to Trees in the Median Median No Improper Driving Non-Fatal Injury NB Daylight Cloudy Dry Lost control of vehicle due to slowing traffic and hit another vehicle on the right side Travel Lane to Median Guardrail to the Right Guardrail to Breakdown Lane Median Followed too closely Non-Fatal Injury NB Dark - Lighted Clear Dry Vehicle hit another vehicle on the right side and caused the vehicle to collide into the median guardrail Travel Lane to Median Guardrail to the Right Guardrail Median Exceeded Speed Limit Non-Fatal Injury NB Daylight Cloudy Wet Vehicle rear ended another vehicle and caused the vehicle to strike the guardrail Travel Lane to Median Guardrail Median Failure to keep in proper lane Not Reported SB Daylight Clear Dry Lost control of vehicle and overturned Travel Lane to Trees in the Median Median Operating Vehicle in Erratic, Reckless Manner and Alcohol Property Damage Only NB Daylight Clear Dry Vehicle tried to avoid a raccoon and overturned in the median Travel Lane to Median Guardrail on S/B Median Swerving or avoiding due to animal in roadway Non-Fatal Injury NB Dark - Not Lighted Not Reported Dry Driver dropped his cellular phone, veered to the right and overcorrected Travel Lane to Breakdown Lane to Trees in the Median Median Over-correcting/Over-steering Property Damage Only NB Dark - Not Lighted Snow Snow Vehicle struck a piece of metal debris and swerved into median Travel Lane to Median Median No Improper Driving Property Damage Only NB Daylight Rain Wet Vehicle hit standing water and hydroplaned Travel Lane to Median Guardrail to the Right Guardrail Median No Improper Driving Non-Fatal Injury SB Dark - Not Lighted Clear Dry Driver operated the vehicle in erratic manner, rear ended another vehicle and crossed the median S/B Travel Lane to N/B Grass Area Adjacent to Breakdown Lane and Northbound On-Ramp Cross Median Operating Vehicle in Erratic, Reckless Manner Fatal Injury NB Daylight Clear Dry Crash avoidance with vehicle from slowing traffic Travel Lane to Median Barrier to Grass Infield of the Ramp Complex Median Followed too closely Property Damage Only NB Dark - Not Lighted Clear Dry Lost control of vehicle for unknown reason Travel Lane to Median Barrier (Construction Zone) Median Failure to keep in proper lane Property Damage Only NB Dark - Not Lighted Clear Dry Lost control of vehicle, veered off roadway and vehicle caught on fire N/B Travel Lane to S/B Travel Lane Cross Median Alcohol Non-Fatal Injury NB Daylight Clear Dry Vehicle was rear ended by another vehicle and skidded into the median guardrail Travel Lane to Median Guardrail Median Followed too closely Property Damage Only NB Dawn Cloudy Dry Vehicle rear tire blew out and overturned Travel Lane to Median Median No Improper Driving Property Damage Only NB Dark - Not Lighted Clear Dry Vehicle rear ended another vehicle and caused the vehicle to struck the guardrail Travel Lane to Median Guardrail to Travel Lane Median Exceeded Speed Limit Property Damage Only NB Dark - Not Lighted Cloudy Dry Driver failed to negotiate on ramp and traveled across all travel lanes Travel Lane to Median Median Operating Vehicle in Erratic, Reckless Manner and Alcohol Non-Fatal Injury NB Dark - Not Lighted Cloudy Dry Vehicle tried to avoid deer and overturned Travel Lane to Median to Breakdown Lane to Ditch on the Right Side Median Swerving or avoiding due to animal in roadway Non-Fatal Injury NB Daylight Clear Dry Driver swerved from the left travel lane to the right travel lane, overcorrected and overturned Travel Lane to Median Guardrail to Right Guardrail to the Right Embankment Median Over-correcting/Over-steering Non-Fatal Injury SB Dawn Clear Dry Vehicle left front tire blew out Travel Lane to Median Guardrail to Travel Lane Median No Improper Driving Non-Fatal Injury SB Daylight Clear Dry Vehicle tried to pass a tractor trailer, struck the right side of the trailer and spun into the guardrail Travel Lane to Median Guardrail to Middle of the Median Median Failure to keep in proper lane Property Damage Only SB Not Reported Rain Wet Vehicle hit standing water and overturned Travel Lane to Trees in the Median Median Driving too fast for condition Property Damage Only SB Dark - Not Lighted Clear Dry Unknown vehicle swerved into travel lane and caused other vehicle to leave roadway and overturn Travel Lane to Median Embankment (Construction Zone) Median Failure to keep in proper lane Property Damage Only SB Daylight Cloudy Dry Vehicle tried to avoid tire debris on the roadway Travel Lane to Trees in the Median Median Swerving or avoiding due to object in roadway Property Damage Only SB Dark - Not Lighted Clear Dry Vehicle rear ended another vehicle and traveled off to the median Travel Lane to Median Median Exceeded Speed Limit and Alcohol Non-Fatal Injury SB Dark - Not Lighted Clear Dry Vehicle rear ended by another vehicle and overturned Travel Lane to Median Embankment Median Exceeded Speed Limit Non-Fatal Injury SB Daylight Clear Dry Vehicle was cut-off by another vehicle, which drifted into his travel lane Travel Lane to Median Guardrail Median Operating Vehicle in Erratic, Reckless Manner Non-Fatal Injury NB Dark - Not Lighted Clear Dry Lost control of vehicle and ran off road left Travel Lane to Median Median Exceeded Speed Limit and Alcohol Unknown